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Plant Profiles

Ferny Hellebore

As Winter thaws reluctantly into Spring, hellebores emerge with their usual fearless urgency. By surprise, it seems, flowers and foliage are now present. The picture above shows new stems in late March. A week later, the unique thin-leafleted leaves are expanding and the first of the flower buds is opening.

As charming as the modest green blooms are, they are only an early-season lagniappe to this hellebore's peak display of foliage from mid-Spring through Fall frosts.

Blossoms of Helleborus multifidus subsp. hercegovinus are apple green, with a crowded and astonishingly fecund-looking mound of pollen-bearing stamens surrounding a trio of the female parts, which are known as carpels.

Lovely but, as I say, just the beginning. Ferny hellebore is grown for foliage, not flowers. Fully deciduous even in mild climates, it provides no Winter display at all. And its show peaks when "normal" perennials do, in June—but holds steady through the early frosts of Fall. The stiff quill-like foliage becomes so dense that, in Summer, a mature clump seems to be an obscure dwarf conifer.

Here's how to grow this remarkable hellebore:

Latin Name

Helleborus multifidussubsp. hercegovinus

Common Name

Ferny Hellebore

Family

Ranunculaceae, the Buttercup family.

What kind of plant is it?

Deciduous perennial.

Hardiness

Zones 4 - 8.

Habit

Multi-stemmed and clumping. Each leaf of a mature plant is divided into an astonishing number of stiff quill-like leaflets: Fifty per leaf is the low-ball; a hundred and eighty-five is among the highest recorded. (With just eight, ten, or twelve leaflets, the leaves of my young plants are still in the foothills of the Himalaya.)

Rate of Growth

Medium.

Size in ten years

A clump about two feet across and about a foot tall.

Texture

Sui generis. At first glance, a mature clump might be mistaken for a dwarf cultivar of the quill-needled conifer, Sciadopitys verticillata. A respective but, still, exploratory fingering only deepens the mystery, in that the "needles" are actually leaflets of a heretofore unimaginable clumping perennial. I will never forget my first encounter with this hellebore. I was dumbfounded and, therefore, ecstatic: here was a plant about which, at the moment, I didn't have a clue. And, to learn that it was a hellebore? Astounding.

Grown for

its foliage, not its flowers: The thin leaflets are unique in hellebores, whereas the small green flowers are typical of many other hellebore forms.

Flowering season

Depending on your climate and the mildness of the cold months, from late Winter to early Spring. Here in southern New England, that's March into April.

Color combinations

Thanks to its all-green palette—flowers, too, not just the leaves—ferny hellebore goes with everything.

Partner Plants

Neighboring plants can add to your hellebore's display even as they also make its circumstances more congenial. The branches of deciduous shrubs and trees that are nearby or even overhead can provide welcome shade in the Summer, but full visual and climatic exposure in Winter. Choose them with two attributes in mind: that the shade they provide in warm weather is dappled not dark, and that they aren't so unattractive when leafless as to detract from the hellebore.

Shrubs are trickier because their Summer shade is so much closer to the ground, and so many are multi-stemmed and therefore fairly dense in both branch and leaf. Those that also provide a Winter display are ideal for hellebores that are evergreen. True, ferny hellebore is deciduous but, even so, its flowers and foliage will have emerged a month or more before that of a shrub. Plus, hellebores all tend to prefer the same quirky circumstances—sweet, gravelly, well drained soil that is, nonetheless, moisture-retentive—so, since you're going to the trouble anyway, create a larger planting area for multiple hellebores. And most of them will be more-or-less evergreen, and deserve companion plants with decent Winter interest. If you take care to thin the shoots of Siberian dogwood, coppiced willows, or box elders—which can otherwise be very wide and dense shrubs—they would be the ultimate.

Shrubs and small trees with wider canopies but few and steeply-ascendant branches or trunks at ground level—especially if they have good Winter interest—save you the trouble of such Spring and Summer thinning. Tree clethra, stewartia, and Japanese maples are at the top of my list.

You can also partner this helleborewith lower neighbors or even groundcovers that look presentable from earliest Spring through late Fall. If you take care that its sprawling stems don't smother the hellebore's foliage, variegated vinca is probably the most reliable; the all-green forms are too high and vigorous. Lysimachia nummularia 'Aurea' is another possibility, provided that your soil is the helleboric ideal of well-drained but also moisture retentive. The dwarfest forms of hosta—which can have rounded leaves scarcely bigger than plums, on plants only as large as your fist—would be terrific in the foreground. Their foliage can be gold or blue, and an effective contrast in either shade. Consider, as well, the smaller of the hardy gingers, such Asarum europaeum. Its rounded, shiny, overlapping leaves form a carpet only inches tall, above which the stiff hellebore leaves would be triumphant. The larger Asarum canadense is so high and vigorous that it would be likely to steamroller right through the hellebore.

Helleborus multifidus is the exception to the partnership of shade-loving ornamental grasses and hellebores: Its narrow foliage is already grassy. So, for once, avoid pairing a hellebore with Hakonechloa, Carex, Liriope, or Ophiopogon.

Where to use it in your garden

Most hellebores are grown mainly for their cold-season flowers and (in mild-enough climates) stalwart evergreen foliage. Hence, they need to be sited where you can access them even when the weather is at its chilly worst, and the ground is squishy at best. By contrast, ferny hellebore is grown mainly as a foliage plant, but one that is deciduous even in mild climates. The plant is entirely without Winter interest. Instead, it is at its best from late Spring through Fall, when the year's new crop of foliage is fully enlarged, and long after the early-Spring flowers are only a memory. So, you needn't dedicate prime Winter-accessible space to Helleborus multifidus: you'll be visiting it mainly in the warmer months, when the grass is walkable and you won't mind exploring the farthest reaches of your horticultural empire. In every sense, ferny hellebore is the anti-hellebore, at its most effective as a warm-weather foliage tour de force that you've sited far from the right-near-the-doors-or-windows spots that, in any event, should already be crowded with Winter-is-my-only-moment beauties.

Whichever spot you honor by including it, ensure that Helleborus multifidus subsp. hercegovinus receives either dappled sun all day, or morning sun followed by dappled sun. This is the plant that welcomes anything taller to the west.

Ferny hellebore is so intriguing that you may even want to feature it as a container plant. See "How to handle it: Another option—or two!"

Culture

Excellent drainage, especially in Winter—but not achieved in soil that's too dry. See "How to handle it: The Basics." Full sun only where the plant wouldn't be stressed by drought. Yes, hellebores are generally quite drought-tolerant: their thick foliage can resist evaporation, and some other forms are able to relinquish their foliage entirely during a hot dry Summer. But ferny hellebore is grown exclusively for its warm-weather foliage display. The ideal is not that the plant merely survives the rigors of the warm months, but that those rigors have been finessed such that the plant is enjoying the Life of Riley from Memorial Day through Halloween.

How to handle it: The Basics

Hellebores should be planted with the same view into the distant misty future that you adopt—or should—when siting peonies. They resent disturbance and, at least when happy, are permanent. It's a challenge to supply both the rich soil and the great drainage that are described in the same breath as being essential. Planting on a slope, no matter how modest, is one solution. Another is to grow hellebores in raised beds—at the top of a masonry wall, say—or even in winter-hardy containers, provided that neither siting also subjects the plants to drought.

The other way to lower the risk of drought stress (and the reduced rate of growth and lower count of leaflets that it is likely to cause) is to provide some shade. Pick a location that provides dappled shade all day, or full sun in the morning and solid shade in the afternoon. Hellebores partner well with deciduous shrubs, whose bare stems can also provide welcome dappled shade in Summer, but let almost all the sun through in Winter and early Spring. See "Partner Plants" above for some possibilities.

Sweet soil is the third goal to strive for. You could incorporate lots of marble chips into the planting bed; marble is a form of limestone. Mulching with gravel is always a good idea, because this helps speed surface drainage. Use marble there, too—even though you'll then be looking at these bright-white stone chips as much as the plant they are mulching. Tone the marble chips down by topping them with a thin layer of buckwheat- or cocoa-hull mulch.

How to handle it: Another option—

or two?

Ferny hellebore is still so deliciously shocking that you may want to grow a clump in a container, to display the plant even more prominently when it's in leaf from early Spring through hard frosts in Fall. A tall pot is probably best, because hellebore roots are capable of penetrating a foot or two deep when growing in the ground. Use nutrient-rich soil that you've mixed with one-third gravel and one-third sharp or builder's sand. Cover the top of the soil with a half-inch of the sand or gravel, too, so that surface water doesn't collect, even for a moment, at the clump's crown.

All of this sand and gravel will make for a heavy pot—and one that you'll probably need to move off stage when the clump has died down to the ground for the Winter, and back to your choicest semi-shady spot in Spring. So use a tall, deep, plastic nursery pot that you can set into a stylish cachepot.

Be attentive about watering during the warm months, especially because you shouldn't set the pot in a saucer to retain the excess water. You want it to drain away. Don't allow the pot to become dry, but don't provide so much water that there's any danger of keeping even sandy, gravelly soil too moist. As I say, be attentive.

After hard frosts have triggered leaf shedding, bring the now-dormant potted clump into a bit of shelter. If you live in Zone 6, an unheated greenhouse or garage would be fine. If your climate is colder, store anywhere that's chilly but not so cold that the root mass freezes solid. If you live in Zone 7, you could probably just move the container alongside your house or greenhouse. In Zone 8, move the container only if its leafless-in-Winter occupant is distracting in its vacancy. When the clump is dormant, water just enough to prevent the soil from becoming dry, which might not be more than once a month if the air in your overwintering location isn't dry.

Be alert for emerging growth, which, because of your having placed the container in shelter, might begin appearing much earlier than that of ferny hellebores growing in the ground. If you have a cool (in all senses) spot indoors that provides plenty of sun (in Winter it's weak, and the hellebore will probably enjoy all the sun it can get), enjoy your ferny hellebore in flower as well as in leaf, as an elegant and still-rare houseplant. Move the plant outside only after the weather has become mild enough that your in-ground hellebores have produced their new crop of foliage.

Quirks or special cases

None.

Downsides

Ferny hellebore can be difficult to source.

Variants

There are no named forms of this subspecies that are readily available.

Availability

Online but only rarely. Buy this hellebore when you can find it, and worry about where to plant it later.

Propagation

By division, by seed, and by tissue culture.

Native habitat

Helleborus multifidussubsp. hercegovinus is native to Bosnia and Herzegovina.